186 AMOUNT OE ALCOHOL IN WINE. 



Mayer obtained, as a precipitate by ammonia, 1*147 

 1*129 1*139 per cent, phosphate of ammonia and 

 magnesia, and also sulphuric acid, lime, and tannic 

 acid, and 0*38 per cent, ashes. The great quantity of 

 phosphate of magnesia which may be precipitated 

 from wine by means of ammonia, as double salt, is a 

 proof of the genuineness of Malaga wine, since from 

 no other wine is it obtained in like abundance, though 

 of course, all wines which have been exposed to eva- 

 poration must yield more than such as have not been 

 subjected to this process. 



If we confine ourselves for the moment to the alco- 

 holic contents of the most excellent wines, we shall 

 find that even thus we are able to determine them, 

 although the results obtained by the different analyses 

 may at first sight seem to vary. 



Port is one of the wines which is richest in alcohol. 

 Grinjal has stated that genuine Port wines never con- 

 tain more than 12*75 per cent, pure alcohol, and is of 

 opinion that those who discovered more in such wines 

 either analysed a wine which had been adulterated 

 with alcohol, or were unable to determine accurately 

 the strength of the alcohol. 



It is difficult to pronounce upon this opinion of 

 Ginjal's out of Portugal. But we may be permitted 

 to ask one question. How is it that all who have 

 analysed Port wine have found from 17 to 21 per cent, 

 alcohol ? Is there no wine except such as is adul- 

 terated with alcohol exported from Portugal ? And 



